PROJECT SUMMARY The EPICENTER project is the first to explore how opioids are prescribed in safety net clinic populations by linking four powerful datasets. Building on our prior experience, we use electronic health record (EHR) data from the OCHIN (not an acronym) practice-based research network that serves over 1.5 million active patients in 581 community health centers (CHCs) in 18 states. We explore multilevel variables within the EHR that shed light on the reasons for receiving chronic opioid prescriptions and associated health outcomes. In order to do so, we link patient records to measures of community social determinants of health. For the 201 OCHIN clinics in Oregon we link EHR records to Medicaid administrative claims as well as vital statistics data. This allows us to examine associations between chronic opioid therapy and outcomes such as opioid overdose and death. The specific aims are: Aim 1: To describe trends of opioid prescribing overall, by strength (morphine equivalence), formulation (long vs. short acting), chronicity of use (acute vs. chronic) and co-prescribing with benzodiazepines in safety net/community health centers and compare them with national trends. Aim 2: To assess the relationship between opioid prescribing (including strength, formulation, chronicity, and co- prescribing with benzodiazepines) and multilevel factors such as patient-level demographics (race/ethnicity, sex, % federal poverty level, etc.) and diagnoses, community-level social determinants of health and clinic- level factors (size, rurality, provider type) in safety net CHCs. Aim 3: To examine the relationship between opioid prescribing (including strength, formulation, chronicity, co-prescribing with benzodiazepines) and relevant health outcomes (co-morbidity, overdoses) in a safety net/CHC population. The proposed work uses unique, rich datasets (EHR, community-level factors, state vital statistics and Medicaid claims data) in a longitudinal research project of ten years (2009-2018) in order to provide a multidimensional assessment of problematic opioid prescribing in community health centers. By focusing on safety net clinics, we will better understand how and why this problem arose in the communities and populations it has most affected in order to understand what policies will lead to better practices and outcomes.